ignition back feed

[zx_volcane]

Don't you just love electrical fault tracing?

So this morning met with flat battery on the black 3 door zx

Jumped it and turned the ignition off - engine still going

Interesting

pulled the stop solenoid plug and it cut out so not the solenoid

ignition lights still on with key removed

pulled shroud round ignition barrel and disconnected all plugs

ignition still on so ruled out the barrel

discounted feeds to starter and alternator, ignition still on - so not back feeding through these

damn, only leaves the loom

wiggled everything i could see, no joy

cue lots of loom nonsense, tracing under wiper scuttle, under nearside arch, blah blah blah

all looks ok, no shorting ..etc

bit more hunting with the multimeter to see if an components are live, found the radiator was showing a about half a volt

and found down the offisde side of the radiator the alarm feed cable was shorting itself out.

nice >

[cully]

good find!
could easly been on fire when you went to it

[Joe]

right, so that little short was causing it to carry on running? so in theory if you link those 2 wires you could bump it?

[zx_volcane]

It was shorting against the radiator / chasis and putting 12v back through the earth and through the whole system.

You can bump a diesel by just putting a live feed from the battery to the stop solenoid.